Leash Walking Sanity Check (am I doing the right thing)?

Background, 10.5-month-old chonky pup (2/3 of my weight). He is very well behaved the only headache I've been having and the main thing that I've been working on is leash walking. It's a very slow process and I've gotten a lot of outside help. We are currently going to 1 on 1 puppy classes. He is finally gotten better. The main "issue" is that we live in new york city so there's a lot of distractions and he gets extremely excited when he sees other dogs (sometimes pigeons and rats 🤦‍♀️). I walk him twice a day for about 2 hours. I've mainly been using the if-he-pulls-I-stop method, treats when he is doing well (ex: back to check on me, walking beside me etc...), going out when it's off dog-walking rush hours (~1pm/11pm), cross the road when I see other dogs coming. We are slowly making progress!

As he got better at loose leash walking, I started doing this (not really strategic, it just kinda happened): when he continues to get too excited and when I feel like I'm about to lose patients. I'd keep him on a short leash for a little bit (often less than a minute) then he gets his loose leash privilege back. Keeping him on a short leash is more for me to calm down and get over frustration than anything else. If I just stop then he gets impatient would start whining or start pull towards things around us. However, I'm starting to wonder if that's a good way to handle the situation.

Today, we went out for our lunch walk. He was doing well for the first 2 blocks. Then he pooped (most stressful part of his walks for me). I cleaned up and just when I was about to throw the poop in the trashcan, he started sprinting towards a pigeon. Unfortunately, it was at an awkward angle, and I didn't have the leverage to stop him right away. I ended up getting dragged behind him towards the pigeon, and then the dog that's on the other side of a verticle advertising billboard he discovered thanks to the pigeon (the other dog owner obviously wasn't pleased by the surprise). I was only able to stop us because I got slammed into a metal railing close to the billboard and my hand with the poop bag still in naturally and instinctually landed on the bag of poop over the metal bars. After the incident, I tried to keep my cool and kept him on a short leash for the next block. Maybe because I kept the leash too short or maybe because he was still very excited. He slipped out of the leash. At that point, I called him back with an angry voice (thankfully he has very good recall) put him back on a short leash, and walked straight home. The shortest walk we've ever had! After I dropped him off at home, I immediately stepped out to get coffee and cool down.

So now I'm thinking maybe it's not a very good idea putting him on a short leash to "cool down." I also felt bad that I didn't praise him for the recall and was worried that he'd associate coming back to me when off-leash with getting in trouble and going home directly. Any thoughts and advice? Thanks very much in advance!